We need an envoy in Mexico. Vote on it!

Despite the political and policy differences among recent presidents, all at one time or another have emphatically reaffirmed the importance of maintaining a constructive and friendly relationship with Mexico.

President Ronald Reagan called relations with Mexico “one of the highest priorities of our administration.” Every president since then has said much the same, and acted accordingly by nominating some of this nation’s most trusted and experienced public servants to manage relations with Mexico. President George H.W. Bush’s Mexico ambassador, John Negroponte, later became the nation’s first director of national intelligence under President George W. Bush.

Today, that relationship is more important than ever, thanks to heightened concern over terrorism and the importance of border security.

Unfortunately, the United States has not had an ambassador in Mexico City for four months, and some members of the Senate appear determined to keep it that way no matter how much that damages U.S. relations with Mexico. The delay in filling the position has nothing to do with Mexico or the qualifications of President Obama’s nominee for the job.

Never miss a local story.

Sign up today for a free 30 day free trial of unlimited digital access.

Roberta Jacobson, who was tapped for the job six months ago, is being held up because, in her role as assistant secretary of State for the Western Hemisphere, she successfully managed the policy breakthrough that resulted in the normalization of relations with Cuba.

In the view of some members of the U.S. Senate — particularly GOP Sen. Marco Rubio of Florida and Sen. Robert Menendez of New Jersey, a Democrat — the problem is that she performed her assigned task all too well, helping to end more than half a century of diplomatic estrangement between the two countries.

First, they bottled up her nomination in the Foreign Relations Committee for four months with delays and holds. Now they are holding up a vote on the Senate floor with similar delaying tactics. That is both unfair to the nominee and damaging to the U.S. national interest. Sens. Rubio and Menendez have the right to oppose the Obama administration’s policy on Cuba — or any other, for that matter — but it is wrong to punish Ms. Jacobson for doing her job, or to cripple U.S.-Mexico relations because of a policy dispute involving an unrelated third country.

As a senior diplomat in the State Department, Ms. Jacobson’s career spans the administrations of the second President Bush and President Obama, in both of which she has held a number of high-level positions dealing with Latin America. If confirmed, she would become the first woman to serve as U.S. ambassador to Mexico.

Relations with Mexico cover the full range of issues. These include energy, drugs, education, human rights and border security. The two nations exchange $1.3 billion in goods over the U.S.-Mexico border each day. Yet without a confirmed ambassador in place, the relationship is effectively on hold, which does no one any good.

In his 1988 radio address, President Reagan declared: “The peoples and governments of the United States and Mexico are and ought to be friends. Our national interests dictate it; our peoples demand it.”

Holding up Ms. Jacobson’s nomination any longer is an abuse of the senatorial privilege. Sens. Rubio and Menendez should let the Senate vote on the ambassadorship before its members go home for Christmas.